The research project is guided by the requirements of the basic cost-benefit-norm. The special norm will establish a cost structure with appropriate definitions, an object catalogue, technological and cost trends, requirements for input data, current/real unit cost, functional relationships, e.g. with traffic volume, asset age etc. Furthermore, a methodology will be described by which the benchmarks can be kept current. The infrastructure cost system will take into account different network elements and their operation and maintenance cost. Network effects by traffic which diverts from principal to secondary roads will also be taken into account.
The Swiss Association of Road and Transport Experts is preparing a basic norm for cost-benefit-analyses of road investment projects. An important element of those cost-benefit-analyses are changes in the operational maintenance cost of the infrastructure. The research project will develop a special norm to establish the respective cost factors and ways for their measurement. The study will complement the new SN 640 907 "Total cost of roads", where road operation and maintenance cost are not treated explicitly.
The first phase of the research project will deal with the cost of day-to-day road operations and maintenance. The intention is, in later phases of the project, to also develop cost benchmarks for road renewal cost as well as operation cost of road users.
For the essential facts of the operational cost road maintenance process or production models for standardized road sections, objects are defined. Based on the models are factory farms asked about the material and the energy demand according to the frequency of measures and according to the process-specific demand for labor and machine hours (roughly categorized). With appropriate cost rates can be determined the appropriate cost codes.
Methods to estimate the operational maintenance costs of roads and therefore a value structure in order to predict the emerging costs of road operation are provided within the cost standard SN 641 826. The estimates can be used to compare reference and project cases of road construction and road management. The standard model to estimate the operational maintenance costs is valid for the majority of roads. However, special circumstances (e.g. winter maintenance in the Alps, exceptional weather conditions, supplementary facilities ...) are not considered in the model. Nevertheless, the individual case has to accommodate such conditions – e.g. by including expert knowledge on road maintenance. In order to use the cost estimating models, information about project scope, traffic, location and time period must be available. The operational costs are divided into four groups:
- operational maintenance,
- traffic control and monitoring by the police,
- administrative costs.
Since constructional and organizational measures primarily exert influence on the operational maintenance costs, this standard focuses on these costs. In order to estimate the operational maintenance costs, evolving from the published Swiss Mean Values, surcharges and discounts on costs are determined, which depend on type, dimension, traffic volume and the surrounding area of the road. Different models are developed to estimate the operational maintenance costs for the different road types (motorways, tunnels and other roads). Traffic volume, road age and environment, as well as altitude and tunnel length (where applicable), are identified as the influential factors of operational maintenance costs. With these inputs, operational maintenance cost estimations can be computed easily.
During the specified time period, the operational maintenance costs are subject to change, since on one hand the preconditions on environment or operation may change (e.g. increased traffic volume or deterioration of installations). On the other hand, technical progress results in cost changes, for which prognostic models are developed too.
The operational maintenance costs are very low compared to investment in new construction, extension or reconstruction of roads. During a typical life time of 40 years, the operational maintenance costs account for 5% to, at most, 20% of the present value. However, operational costs are relevant in those cases, where variants with similar investment expenditure are compared.